2 * ip_vs_proto_tcp.c: TCP load balancing support for IPVS
4 * Version: $Id: ip_vs_proto_tcp.c,v 1.3 2002/11/30 01:50:35 wensong Exp $
6 * Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
7 * Julian Anastasov <ja@ssi.bg>
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
18 #include <linux/kernel.h>
20 #include <linux/tcp.h> /* for tcphdr */
22 #include <net/tcp.h> /* for csum_tcpudp_magic */
23 #include <linux/netfilter_ipv4.h>
25 #include <net/ip_vs.h>
28 static struct ip_vs_conn
*
29 tcp_conn_in_get(const struct sk_buff
*skb
, struct ip_vs_protocol
*pp
,
30 const struct iphdr
*iph
, unsigned int proto_off
, int inverse
)
32 __u16 _ports
[2], *pptr
;
34 pptr
= skb_header_pointer(skb
, proto_off
, sizeof(_ports
), _ports
);
38 if (likely(!inverse
)) {
39 return ip_vs_conn_in_get(iph
->protocol
,
43 return ip_vs_conn_in_get(iph
->protocol
,
49 static struct ip_vs_conn
*
50 tcp_conn_out_get(const struct sk_buff
*skb
, struct ip_vs_protocol
*pp
,
51 const struct iphdr
*iph
, unsigned int proto_off
, int inverse
)
53 __u16 _ports
[2], *pptr
;
55 pptr
= skb_header_pointer(skb
, proto_off
, sizeof(_ports
), _ports
);
59 if (likely(!inverse
)) {
60 return ip_vs_conn_out_get(iph
->protocol
,
64 return ip_vs_conn_out_get(iph
->protocol
,
72 tcp_conn_schedule(struct sk_buff
*skb
,
73 struct ip_vs_protocol
*pp
,
74 int *verdict
, struct ip_vs_conn
**cpp
)
76 struct ip_vs_service
*svc
;
77 struct tcphdr _tcph
, *th
;
79 th
= skb_header_pointer(skb
, skb
->nh
.iph
->ihl
*4,
80 sizeof(_tcph
), &_tcph
);
87 (svc
= ip_vs_service_get(skb
->nfmark
, skb
->nh
.iph
->protocol
,
88 skb
->nh
.iph
->daddr
, th
->dest
))) {
91 * It seems that we are very loaded.
92 * We have to drop this packet :(
94 ip_vs_service_put(svc
);
100 * Let the virtual server select a real server for the
101 * incoming connection, and create a connection entry.
103 *cpp
= ip_vs_schedule(svc
, skb
);
105 *verdict
= ip_vs_leave(svc
, skb
, pp
);
108 ip_vs_service_put(svc
);
115 tcp_fast_csum_update(struct tcphdr
*tcph
, u32 oldip
, u32 newip
,
116 u16 oldport
, u16 newport
)
119 ip_vs_check_diff(~oldip
, newip
,
120 ip_vs_check_diff(oldport
^ 0xFFFF,
121 newport
, tcph
->check
));
126 tcp_snat_handler(struct sk_buff
**pskb
,
127 struct ip_vs_protocol
*pp
, struct ip_vs_conn
*cp
)
130 unsigned int tcphoff
= (*pskb
)->nh
.iph
->ihl
* 4;
132 /* csum_check requires unshared skb */
133 if (!ip_vs_make_skb_writable(pskb
, tcphoff
+sizeof(*tcph
)))
136 if (unlikely(cp
->app
!= NULL
)) {
137 /* Some checks before mangling */
138 if (pp
->csum_check
&& !pp
->csum_check(*pskb
, pp
))
141 /* Call application helper if needed */
142 if (!ip_vs_app_pkt_out(cp
, pskb
))
146 tcph
= (void *)(*pskb
)->nh
.iph
+ tcphoff
;
147 tcph
->source
= cp
->vport
;
149 /* Adjust TCP checksums */
151 /* Only port and addr are changed, do fast csum update */
152 tcp_fast_csum_update(tcph
, cp
->daddr
, cp
->vaddr
,
153 cp
->dport
, cp
->vport
);
154 if ((*pskb
)->ip_summed
== CHECKSUM_HW
)
155 (*pskb
)->ip_summed
= CHECKSUM_NONE
;
157 /* full checksum calculation */
159 (*pskb
)->csum
= skb_checksum(*pskb
, tcphoff
,
160 (*pskb
)->len
- tcphoff
, 0);
161 tcph
->check
= csum_tcpudp_magic(cp
->vaddr
, cp
->caddr
,
162 (*pskb
)->len
- tcphoff
,
165 IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n",
166 pp
->name
, tcph
->check
,
167 (char*)&(tcph
->check
) - (char*)tcph
);
174 tcp_dnat_handler(struct sk_buff
**pskb
,
175 struct ip_vs_protocol
*pp
, struct ip_vs_conn
*cp
)
178 unsigned int tcphoff
= (*pskb
)->nh
.iph
->ihl
* 4;
180 /* csum_check requires unshared skb */
181 if (!ip_vs_make_skb_writable(pskb
, tcphoff
+sizeof(*tcph
)))
184 if (unlikely(cp
->app
!= NULL
)) {
185 /* Some checks before mangling */
186 if (pp
->csum_check
&& !pp
->csum_check(*pskb
, pp
))
190 * Attempt ip_vs_app call.
191 * It will fix ip_vs_conn and iph ack_seq stuff
193 if (!ip_vs_app_pkt_in(cp
, pskb
))
197 tcph
= (void *)(*pskb
)->nh
.iph
+ tcphoff
;
198 tcph
->dest
= cp
->dport
;
201 * Adjust TCP checksums
204 /* Only port and addr are changed, do fast csum update */
205 tcp_fast_csum_update(tcph
, cp
->vaddr
, cp
->daddr
,
206 cp
->vport
, cp
->dport
);
207 if ((*pskb
)->ip_summed
== CHECKSUM_HW
)
208 (*pskb
)->ip_summed
= CHECKSUM_NONE
;
210 /* full checksum calculation */
212 (*pskb
)->csum
= skb_checksum(*pskb
, tcphoff
,
213 (*pskb
)->len
- tcphoff
, 0);
214 tcph
->check
= csum_tcpudp_magic(cp
->caddr
, cp
->daddr
,
215 (*pskb
)->len
- tcphoff
,
218 (*pskb
)->ip_summed
= CHECKSUM_UNNECESSARY
;
225 tcp_csum_check(struct sk_buff
*skb
, struct ip_vs_protocol
*pp
)
227 unsigned int tcphoff
= skb
->nh
.iph
->ihl
*4;
229 switch (skb
->ip_summed
) {
231 skb
->csum
= skb_checksum(skb
, tcphoff
, skb
->len
- tcphoff
, 0);
233 if (csum_tcpudp_magic(skb
->nh
.iph
->saddr
, skb
->nh
.iph
->daddr
,
235 skb
->nh
.iph
->protocol
, skb
->csum
)) {
236 IP_VS_DBG_RL_PKT(0, pp
, skb
, 0,
237 "Failed checksum for");
242 /* CHECKSUM_UNNECESSARY */
250 #define TCP_DIR_INPUT 0
251 #define TCP_DIR_OUTPUT 4
252 #define TCP_DIR_INPUT_ONLY 8
254 static int tcp_state_off
[IP_VS_DIR_LAST
] = {
255 [IP_VS_DIR_INPUT
] = TCP_DIR_INPUT
,
256 [IP_VS_DIR_OUTPUT
] = TCP_DIR_OUTPUT
,
257 [IP_VS_DIR_INPUT_ONLY
] = TCP_DIR_INPUT_ONLY
,
261 * Timeout table[state]
263 static int tcp_timeouts
[IP_VS_TCP_S_LAST
+1] = {
264 [IP_VS_TCP_S_NONE
] = 2*HZ
,
265 [IP_VS_TCP_S_ESTABLISHED
] = 15*60*HZ
,
266 [IP_VS_TCP_S_SYN_SENT
] = 2*60*HZ
,
267 [IP_VS_TCP_S_SYN_RECV
] = 1*60*HZ
,
268 [IP_VS_TCP_S_FIN_WAIT
] = 2*60*HZ
,
269 [IP_VS_TCP_S_TIME_WAIT
] = 2*60*HZ
,
270 [IP_VS_TCP_S_CLOSE
] = 10*HZ
,
271 [IP_VS_TCP_S_CLOSE_WAIT
] = 60*HZ
,
272 [IP_VS_TCP_S_LAST_ACK
] = 30*HZ
,
273 [IP_VS_TCP_S_LISTEN
] = 2*60*HZ
,
274 [IP_VS_TCP_S_SYNACK
] = 120*HZ
,
275 [IP_VS_TCP_S_LAST
] = 2*HZ
,
281 /* FIXME: This is going to die */
283 static int tcp_timeouts_dos
[IP_VS_TCP_S_LAST
+1] = {
284 [IP_VS_TCP_S_NONE
] = 2*HZ
,
285 [IP_VS_TCP_S_ESTABLISHED
] = 8*60*HZ
,
286 [IP_VS_TCP_S_SYN_SENT
] = 60*HZ
,
287 [IP_VS_TCP_S_SYN_RECV
] = 10*HZ
,
288 [IP_VS_TCP_S_FIN_WAIT
] = 60*HZ
,
289 [IP_VS_TCP_S_TIME_WAIT
] = 60*HZ
,
290 [IP_VS_TCP_S_CLOSE
] = 10*HZ
,
291 [IP_VS_TCP_S_CLOSE_WAIT
] = 60*HZ
,
292 [IP_VS_TCP_S_LAST_ACK
] = 30*HZ
,
293 [IP_VS_TCP_S_LISTEN
] = 2*60*HZ
,
294 [IP_VS_TCP_S_SYNACK
] = 100*HZ
,
295 [IP_VS_TCP_S_LAST
] = 2*HZ
,
300 static char * tcp_state_name_table
[IP_VS_TCP_S_LAST
+1] = {
301 [IP_VS_TCP_S_NONE
] = "NONE",
302 [IP_VS_TCP_S_ESTABLISHED
] = "ESTABLISHED",
303 [IP_VS_TCP_S_SYN_SENT
] = "SYN_SENT",
304 [IP_VS_TCP_S_SYN_RECV
] = "SYN_RECV",
305 [IP_VS_TCP_S_FIN_WAIT
] = "FIN_WAIT",
306 [IP_VS_TCP_S_TIME_WAIT
] = "TIME_WAIT",
307 [IP_VS_TCP_S_CLOSE
] = "CLOSE",
308 [IP_VS_TCP_S_CLOSE_WAIT
] = "CLOSE_WAIT",
309 [IP_VS_TCP_S_LAST_ACK
] = "LAST_ACK",
310 [IP_VS_TCP_S_LISTEN
] = "LISTEN",
311 [IP_VS_TCP_S_SYNACK
] = "SYNACK",
312 [IP_VS_TCP_S_LAST
] = "BUG!",
315 #define sNO IP_VS_TCP_S_NONE
316 #define sES IP_VS_TCP_S_ESTABLISHED
317 #define sSS IP_VS_TCP_S_SYN_SENT
318 #define sSR IP_VS_TCP_S_SYN_RECV
319 #define sFW IP_VS_TCP_S_FIN_WAIT
320 #define sTW IP_VS_TCP_S_TIME_WAIT
321 #define sCL IP_VS_TCP_S_CLOSE
322 #define sCW IP_VS_TCP_S_CLOSE_WAIT
323 #define sLA IP_VS_TCP_S_LAST_ACK
324 #define sLI IP_VS_TCP_S_LISTEN
325 #define sSA IP_VS_TCP_S_SYNACK
327 struct tcp_states_t
{
328 int next_state
[IP_VS_TCP_S_LAST
];
331 static const char * tcp_state_name(int state
)
333 if (state
>= IP_VS_TCP_S_LAST
)
335 return tcp_state_name_table
[state
] ? tcp_state_name_table
[state
] : "?";
338 static struct tcp_states_t tcp_states
[] = {
340 /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
341 /*syn*/ {{sSR
, sES
, sES
, sSR
, sSR
, sSR
, sSR
, sSR
, sSR
, sSR
, sSR
}},
342 /*fin*/ {{sCL
, sCW
, sSS
, sTW
, sTW
, sTW
, sCL
, sCW
, sLA
, sLI
, sTW
}},
343 /*ack*/ {{sCL
, sES
, sSS
, sES
, sFW
, sTW
, sCL
, sCW
, sCL
, sLI
, sES
}},
344 /*rst*/ {{sCL
, sCL
, sCL
, sSR
, sCL
, sCL
, sCL
, sCL
, sLA
, sLI
, sSR
}},
347 /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
348 /*syn*/ {{sSS
, sES
, sSS
, sSR
, sSS
, sSS
, sSS
, sSS
, sSS
, sLI
, sSR
}},
349 /*fin*/ {{sTW
, sFW
, sSS
, sTW
, sFW
, sTW
, sCL
, sTW
, sLA
, sLI
, sTW
}},
350 /*ack*/ {{sES
, sES
, sSS
, sES
, sFW
, sTW
, sCL
, sCW
, sLA
, sES
, sES
}},
351 /*rst*/ {{sCL
, sCL
, sSS
, sCL
, sCL
, sTW
, sCL
, sCL
, sCL
, sCL
, sCL
}},
354 /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
355 /*syn*/ {{sSR
, sES
, sES
, sSR
, sSR
, sSR
, sSR
, sSR
, sSR
, sSR
, sSR
}},
356 /*fin*/ {{sCL
, sFW
, sSS
, sTW
, sFW
, sTW
, sCL
, sCW
, sLA
, sLI
, sTW
}},
357 /*ack*/ {{sCL
, sES
, sSS
, sES
, sFW
, sTW
, sCL
, sCW
, sCL
, sLI
, sES
}},
358 /*rst*/ {{sCL
, sCL
, sCL
, sSR
, sCL
, sCL
, sCL
, sCL
, sLA
, sLI
, sCL
}},
361 static struct tcp_states_t tcp_states_dos
[] = {
363 /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
364 /*syn*/ {{sSR
, sES
, sES
, sSR
, sSR
, sSR
, sSR
, sSR
, sSR
, sSR
, sSA
}},
365 /*fin*/ {{sCL
, sCW
, sSS
, sTW
, sTW
, sTW
, sCL
, sCW
, sLA
, sLI
, sSA
}},
366 /*ack*/ {{sCL
, sES
, sSS
, sSR
, sFW
, sTW
, sCL
, sCW
, sCL
, sLI
, sSA
}},
367 /*rst*/ {{sCL
, sCL
, sCL
, sSR
, sCL
, sCL
, sCL
, sCL
, sLA
, sLI
, sCL
}},
370 /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
371 /*syn*/ {{sSS
, sES
, sSS
, sSA
, sSS
, sSS
, sSS
, sSS
, sSS
, sLI
, sSA
}},
372 /*fin*/ {{sTW
, sFW
, sSS
, sTW
, sFW
, sTW
, sCL
, sTW
, sLA
, sLI
, sTW
}},
373 /*ack*/ {{sES
, sES
, sSS
, sES
, sFW
, sTW
, sCL
, sCW
, sLA
, sES
, sES
}},
374 /*rst*/ {{sCL
, sCL
, sSS
, sCL
, sCL
, sTW
, sCL
, sCL
, sCL
, sCL
, sCL
}},
377 /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
378 /*syn*/ {{sSA
, sES
, sES
, sSR
, sSA
, sSA
, sSA
, sSA
, sSA
, sSA
, sSA
}},
379 /*fin*/ {{sCL
, sFW
, sSS
, sTW
, sFW
, sTW
, sCL
, sCW
, sLA
, sLI
, sTW
}},
380 /*ack*/ {{sCL
, sES
, sSS
, sES
, sFW
, sTW
, sCL
, sCW
, sCL
, sLI
, sES
}},
381 /*rst*/ {{sCL
, sCL
, sCL
, sSR
, sCL
, sCL
, sCL
, sCL
, sLA
, sLI
, sCL
}},
384 static struct tcp_states_t
*tcp_state_table
= tcp_states
;
387 static void tcp_timeout_change(struct ip_vs_protocol
*pp
, int flags
)
389 int on
= (flags
& 1); /* secure_tcp */
392 ** FIXME: change secure_tcp to independent sysctl var
393 ** or make it per-service or per-app because it is valid
394 ** for most if not for all of the applications. Something
395 ** like "capabilities" (flags) for each object.
397 tcp_state_table
= (on
? tcp_states_dos
: tcp_states
);
401 tcp_set_state_timeout(struct ip_vs_protocol
*pp
, char *sname
, int to
)
403 return ip_vs_set_state_timeout(pp
->timeout_table
, IP_VS_TCP_S_LAST
,
404 tcp_state_name_table
, sname
, to
);
407 static inline int tcp_state_idx(struct tcphdr
*th
)
421 set_tcp_state(struct ip_vs_protocol
*pp
, struct ip_vs_conn
*cp
,
422 int direction
, struct tcphdr
*th
)
425 int new_state
= IP_VS_TCP_S_CLOSE
;
426 int state_off
= tcp_state_off
[direction
];
429 * Update state offset to INPUT_ONLY if necessary
430 * or delete NO_OUTPUT flag if output packet detected
432 if (cp
->flags
& IP_VS_CONN_F_NOOUTPUT
) {
433 if (state_off
== TCP_DIR_OUTPUT
)
434 cp
->flags
&= ~IP_VS_CONN_F_NOOUTPUT
;
436 state_off
= TCP_DIR_INPUT_ONLY
;
439 if ((state_idx
= tcp_state_idx(th
)) < 0) {
440 IP_VS_DBG(8, "tcp_state_idx=%d!!!\n", state_idx
);
444 new_state
= tcp_state_table
[state_off
+state_idx
].next_state
[cp
->state
];
447 if (new_state
!= cp
->state
) {
448 struct ip_vs_dest
*dest
= cp
->dest
;
450 IP_VS_DBG(8, "%s %s [%c%c%c%c] %u.%u.%u.%u:%d->"
451 "%u.%u.%u.%u:%d state: %s->%s cnt:%d\n",
453 (state_off
==TCP_DIR_OUTPUT
)?"output ":"input ",
458 NIPQUAD(cp
->daddr
), ntohs(cp
->dport
),
459 NIPQUAD(cp
->caddr
), ntohs(cp
->cport
),
460 tcp_state_name(cp
->state
),
461 tcp_state_name(new_state
),
462 atomic_read(&cp
->refcnt
));
464 if (!(cp
->flags
& IP_VS_CONN_F_INACTIVE
) &&
465 (new_state
!= IP_VS_TCP_S_ESTABLISHED
)) {
466 atomic_dec(&dest
->activeconns
);
467 atomic_inc(&dest
->inactconns
);
468 cp
->flags
|= IP_VS_CONN_F_INACTIVE
;
469 } else if ((cp
->flags
& IP_VS_CONN_F_INACTIVE
) &&
470 (new_state
== IP_VS_TCP_S_ESTABLISHED
)) {
471 atomic_inc(&dest
->activeconns
);
472 atomic_dec(&dest
->inactconns
);
473 cp
->flags
&= ~IP_VS_CONN_F_INACTIVE
;
478 cp
->timeout
= pp
->timeout_table
[cp
->state
= new_state
];
483 * Handle state transitions
486 tcp_state_transition(struct ip_vs_conn
*cp
, int direction
,
487 const struct sk_buff
*skb
,
488 struct ip_vs_protocol
*pp
)
490 struct tcphdr _tcph
, *th
;
492 th
= skb_header_pointer(skb
, skb
->nh
.iph
->ihl
*4,
493 sizeof(_tcph
), &_tcph
);
497 spin_lock(&cp
->lock
);
498 set_tcp_state(pp
, cp
, direction
, th
);
499 spin_unlock(&cp
->lock
);
506 * Hash table for TCP application incarnations
508 #define TCP_APP_TAB_BITS 4
509 #define TCP_APP_TAB_SIZE (1 << TCP_APP_TAB_BITS)
510 #define TCP_APP_TAB_MASK (TCP_APP_TAB_SIZE - 1)
512 static struct list_head tcp_apps
[TCP_APP_TAB_SIZE
];
513 static DEFINE_SPINLOCK(tcp_app_lock
);
515 static inline __u16
tcp_app_hashkey(__u16 port
)
517 return ((port
>> TCP_APP_TAB_BITS
) ^ port
) & TCP_APP_TAB_MASK
;
521 static int tcp_register_app(struct ip_vs_app
*inc
)
524 __u16 hash
, port
= inc
->port
;
527 hash
= tcp_app_hashkey(port
);
529 spin_lock_bh(&tcp_app_lock
);
530 list_for_each_entry(i
, &tcp_apps
[hash
], p_list
) {
531 if (i
->port
== port
) {
536 list_add(&inc
->p_list
, &tcp_apps
[hash
]);
537 atomic_inc(&ip_vs_protocol_tcp
.appcnt
);
540 spin_unlock_bh(&tcp_app_lock
);
546 tcp_unregister_app(struct ip_vs_app
*inc
)
548 spin_lock_bh(&tcp_app_lock
);
549 atomic_dec(&ip_vs_protocol_tcp
.appcnt
);
550 list_del(&inc
->p_list
);
551 spin_unlock_bh(&tcp_app_lock
);
556 tcp_app_conn_bind(struct ip_vs_conn
*cp
)
559 struct ip_vs_app
*inc
;
562 /* Default binding: bind app only for NAT */
563 if (IP_VS_FWD_METHOD(cp
) != IP_VS_CONN_F_MASQ
)
566 /* Lookup application incarnations and bind the right one */
567 hash
= tcp_app_hashkey(cp
->vport
);
569 spin_lock(&tcp_app_lock
);
570 list_for_each_entry(inc
, &tcp_apps
[hash
], p_list
) {
571 if (inc
->port
== cp
->vport
) {
572 if (unlikely(!ip_vs_app_inc_get(inc
)))
574 spin_unlock(&tcp_app_lock
);
576 IP_VS_DBG(9, "%s: Binding conn %u.%u.%u.%u:%u->"
577 "%u.%u.%u.%u:%u to app %s on port %u\n",
579 NIPQUAD(cp
->caddr
), ntohs(cp
->cport
),
580 NIPQUAD(cp
->vaddr
), ntohs(cp
->vport
),
581 inc
->name
, ntohs(inc
->port
));
584 result
= inc
->init_conn(inc
, cp
);
588 spin_unlock(&tcp_app_lock
);
596 * Set LISTEN timeout. (ip_vs_conn_put will setup timer)
598 void ip_vs_tcp_conn_listen(struct ip_vs_conn
*cp
)
600 spin_lock(&cp
->lock
);
601 cp
->state
= IP_VS_TCP_S_LISTEN
;
602 cp
->timeout
= ip_vs_protocol_tcp
.timeout_table
[IP_VS_TCP_S_LISTEN
];
603 spin_unlock(&cp
->lock
);
607 static void tcp_init(struct ip_vs_protocol
*pp
)
609 IP_VS_INIT_HASH_TABLE(tcp_apps
);
610 pp
->timeout_table
= tcp_timeouts
;
614 static void tcp_exit(struct ip_vs_protocol
*pp
)
619 struct ip_vs_protocol ip_vs_protocol_tcp
= {
621 .protocol
= IPPROTO_TCP
,
623 .appcnt
= ATOMIC_INIT(0),
626 .register_app
= tcp_register_app
,
627 .unregister_app
= tcp_unregister_app
,
628 .conn_schedule
= tcp_conn_schedule
,
629 .conn_in_get
= tcp_conn_in_get
,
630 .conn_out_get
= tcp_conn_out_get
,
631 .snat_handler
= tcp_snat_handler
,
632 .dnat_handler
= tcp_dnat_handler
,
633 .csum_check
= tcp_csum_check
,
634 .state_name
= tcp_state_name
,
635 .state_transition
= tcp_state_transition
,
636 .app_conn_bind
= tcp_app_conn_bind
,
637 .debug_packet
= ip_vs_tcpudp_debug_packet
,
638 .timeout_change
= tcp_timeout_change
,
639 .set_state_timeout
= tcp_set_state_timeout
,